Any of a very large and diverse phylum of Terragen or Terragen-derived metazoa with segmented bodies, jointed limbs, and exoskeletons made of chitin.

Insects, arachnids, crustaceans, myriapods, trilobites, eurypterids, arthropleurids, and Vedokikleks are among a few of the countless millions of kinds of arthropods that have lived in the past or are still alive today. Although most arthropods are small, a few prehistoric and lazurogenic kinds can reach one to two meters in length, and several augmented and geneered forms have been modified to attain many times that size, albeit in low gravity environments.

Although true arthropods are Terragen only, there are many examples of arthropodoidal animals with superficially similar body-structure (albeit different chemistry, metabolism, and anatomy) evolving on a number of worlds. In addition, many hardcopy alifes and neumanns have found the arthropoic form to be the most optimal morphotype for deep space exploration and replication.